Skeletron Prime

Skeletron Prime is the Hardmode iteration of Skeletron and the most powerful Boss in Terraria. He appears as a giant robotic skull with four robotic arms, each wielding a different weapon. Skeletron Prime becomes nearly invincible during daylight hours.

Skeletron Prime appears after being summoned by a Mechanical Skull. All of Skeletron's hands have a different attack. The Prime Cannon fires grenades and isn't always directed at a player. The Prime Laser shoots Lasers similar to The Destroyer, and is always aimed at a player. The Prime Saw sweeps back and forth dealing large melee damage and homes in during headspins. The Prime Vice also swipes around but doesn't home in during headspins